Modern vehicles and other structures utilize many systems, such as lighting and electronics, that have various separate components. For example, the systems may have dedicated components, such as receptacles, controls and/or displays, and shared components, such as power supplies and processors. The components may be located remotely from each other, which necessitates cables, including wires, to connect the components for the systems to function properly. Thus, the cables may span a considerable length depending upon the locations of the components relative to one another. It is typically desirable to enclose the cables in tubes, such as raceways, that extend along a relatively secluded area of the vehicle or structure in order to protect the cables and the people in the vehicle or structure. Often, however, the raceways are filled with cables or are otherwise accessible and the system installers must extend bundles of cables through another area of the vehicle or structure.
The cables outside of the primary raceways are typically assembled into bundles and secured using a variety of fasteners, such as nylon-type clamps and saddle-brackets. It is essential that the clamps are installed without damaging the cable bundles in order for the systems that the cables support to function properly. It is also important that once the cable clamps are installed, they remain in place when subjected to various vibrational and other forces that the structure containing the cables and clamps may encounter to prevent damage to the cables, such as by abrasion between the cables and the clamps. For example, modern aircraft require hundreds of clamps to secure the many cables that connect the systems and extend along the interior of the aircraft. To ensure the cables are out of the way of passengers or crew onboard the aircraft, some of the clamps may be located in relatively secluded areas of the aircraft that may be difficult to reach, such as stow bins, side panels and/or ceiling panels.
Conventional cable clamps are typically in the form of a P-clamp or elongated strap in combination with a fastener. For example, U.S. Pat. Nos. 4,813,105 and 5,354,021 are clamps used in the aviation industry that utilize an adjustable flexible strap to secure the cable bundle, as well as a fastener to attach the assembly to a structure. Conventional cable bundle clamps require at least one, and typically two, items of loose hardware and structural provisioning for each attachment to add support to a portion of cable weighing only a few ounces. For instance, in order to install most cable bundle clamps, a hole must first be drilled into a secondary structure face sheet, such as in stowbins or interior panels. A clamp or bracket is positioned around the cable. Then, potting compound and a steel insert is placed within the hole to provide an “anchor” for a screw that is inserted through a hole in the cable clamp or bracket and within the potting to secure the assembly onto the face sheet. Therefore, conventional cable bundle installation generally requires many pieces of loose hardware and tools to assemble the clamps. Consequently, when installing cable bundles in tight areas, it is difficult to use the tools and manage the small parts. In addition, each interior cable bundle requires enough cable clamp attachments to keep the clamps spaced less than one foot apart for proper support. Because of this difficulty and the multiple number of clamps that must be installed, the conventional installation process is labor-intensive and time consuming.
Frequently, it is also desirable to stack cable bundles in “Christmas tree” fashion by arranging the clamps in a stack using one fastener. Therefore, when one clamp is in need of repair or removal, several other clamps will first require removal with tools before enough space is created to reach the cable bundle clamp requiring attention, which is also labor-intensive and time-consuming for the installer. In addition, when stacking clamps of this type, cable management is difficult because there is no way to ensure that certain types of cables, such as those for the electrical systems, are grouped together. Without cable management, trouble shooting and movement of only certain systems and their associated cables is difficult.
Furthermore, a slight change in the location of a component of a system may require the cable bundle routes to change, which, at the least, requires a significant amount of time and labor to remove the clamp fasteners and clamps with tools and reinstall them in the new location. In some cases, the structural designers/engineers may have to revise the structure to accommodate the new cable bundle attachments due to the space required and structural support needed for installation. Thus, because new holes must be drilled and new potting compound and/or steel insert applied, the existing structure may not be able to withstand the extra weight. This is most prevalent on passenger interior commodities of an aircraft, such as in sidewalls, stowbins, and ceiling panels, which may be made of lightweight materials, such as composite face sheets over a honeycomb-type core material. In addition, the structural panels cannot provide a grid of inserts to allow for many possible cable bundle installations because of the excessive weight of the inserts and the prohibitive expense of the labor involved in the tedious process of preparing for attachment that may not be utilized.
Another clamping technique utilizes an adjustable strap with one hole at a first end and a series of holes arranged linearly near the opposed second end, such that the fastener may be inserted through both the one hole and an appropriate hole selected from the series of holes near the second end. As such, the strap forms a loop through which the cable or cables to be secured to the structure may extend. The fastener includes an expandable member that is inserted into a hole of appropriate size in the structure after also being extended through the holes of the strap. A pin is then inserted through the expandable member, which expands the expandable member to secure the clamp to the structure. While this clamping technique is useful because it eliminates the need for tools, potting compound, and steel inserts, the strap feature with many holes along one end does not provide a strong enough clamp for cables in many applications that are subjected to relatively large forces, such as frequent movements and vibrations. Thus, if the strap is wrapped around many cables or one large cable, then the loop that extends about the cable(s) will include a larger number of the holes, which is the weakest part of the strap. Thus, the strap is more likely to break. In addition, because there is no way to cinch the strap securely around the cables since the locations of the holes in the strap are predetermined, then the cables may be loose in the strap, which could cause the strap to rub against the cables and damage the cables such that the systems supported by the cables may become inoperable. Furthermore, the straps may not be stacked due to the short length of the pin.
There is, therefore, a need in the industry for an improved technique for tightly securing cables to a structure and permitting the cables to be released to more easily install and reroute cable bundles. It is also desirable to eliminate the need for tools to secure cables to a structure, which will permit the cables to be more readily installed in limited access areas and easily released when removal is desired. In addition, an improved technique for separately securing a number of cables in an orderly fashion is desired for the purposes of cable management. Furthermore, there is a need for a quick release cable clamp that is strong enough, and secures the cables tightly enough, to withstand the weight of heavy cables and forces, such as vibrational forces, without damaging the clamp or the cables.